Glass-drawing apparatus.



GILASS DRAWING APPARATUS. APPucATloN man 1AN.26.. 19.16.

1.,17|9,250. Patented Apr. 11,1916.

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Speeieationcof Letters Eatent. Y Patente@ A L i,iliy 1191i@ l Application Bled January 26, 1916. Serial No. 74,467.

To all whom it may concern Be it known-that i, WiLLIAiu-lns'r'mrr, a citizen of the United States, residing at lOkniulgee7 in the county ci' Okmnlgee and State of Oklahoma, have invented new andf useul improvements in Glass-Drawing Apor connection between the cylinder and the bait. This is -due to variations of temperature between the bait and outside atmosphere and between the inner and outer sur.-y

taces of the initial portion of the cylinder, by which the interior and exterior surface tension of the glass at 'and adjacent to the .neck is rendered unequal, whereby breakage of the neck is `liable to occur owing,- 'to 1in-- equal 'expansion and contractionwhen theA bait is cooled-by exposure to the atmosphere and the air supplied to the' cylinder in theprogress of the draw. Another cause of the formation of an imperfect neck or breakage of the same is often due to the premature admission o-air to the interior of the cylinder at the beginning of the drawing operation, whereby the bait is chilled unduly be! fore the cylinder liardensA suliciently for tirni adhesion thereto, the resulting con-- traction ot' the bait and unequal contraction 40 of the neck causing the separation of these. parts or fracture of the neck and an abortive drawing action. In many cases the too sudden turning on of the air blows the walls of the neck of the cylinder out `against the side ofbait or blow pipe whilethe pipe is at the highest temperature, and as the'bait cools quickly the neck-is crushed yby ccntraction.

lThe primary object of the inventionils to v provide a drawing tool which is so constructed as to insure a supply of air to the interior of the cylinder for a suiiiient time'atthe.

beginning of the-draw to eiiect fthe fornafA tion of a perfect neck4 having substantially.'

5&5 equal interior and exterior surface tension and capability of'expansionand'contraction5 whereby any tendency of ,theneclv to sepan ratefroni the bait or to break as a result of uzneqjiall surface tensions and contraction and expansion will. be avoided.

' A further object of theinventipn is vprovide means whereby the supply of' air from the source or compressed air supply to vthe cylinder will. Vbe deterred at the begin ning of ,the draw for a sutlicient yperiod to prevent undue cooling and contraction ot the bait prior toA the formation oi' the neckn by which the production of a perfect neck or connection between 'the cylinder' andbait will be further insured.

Thefinvention `Consists of the features of construction combination and arrangement of parts herein fully described and claimed., reference being had to the accompanying drawing in which Figurel is a sectional elevation showing the tool in connection with a source of 'glass supply, with the parts arranged as at the beginning ot' the draw. Fig. 2 is a similar View showing the partis as they appear after the cylinder is partially drawn. Fig. 3 is a sectional View through the complete bait as itappears when the hollow bait body closed at ton by the blow head. i

Referring to the drawing, l designates a dogliouse ,or otlierreceptacle containing asupply of molten glass 2 from which the cylinders are to be formed,- and 2 designates a Icarriage 'movable -vertically upon suitable track rails' 3 and which forms a support for 'the drawing` tool. .This carriage is adapted ,to be raised andlowered in any suitable manner or by-any of' the means coininonly employed.v I have not considered it neces-- sary to, show any raising' Vand loweringr 'rneans, as the same forms nov part of the Siiv present invention and as any known type of carriage .controlling means may be used.

The bait embodying niy invention is formed of two sections and comprises a hollow bait body l and a valve or closuremember 5. The bait body i may be, as shown, in the form of an: inverted truste-conical body con sisting of a bottom wall 6 side wall Z and top wall 8. This body is of hollow torination for the purpose of securing desired cool `ing effects, and is provided in its bottom and top walls with air inlet .openings 9 and 10, the .wall of the upper opening 10 being doubled to-orm a valve seat. The body et is arranged below the carriage 2 and supported 11, while the valve or closure member 5 is fixed to the lower end of a vertically movable air supply or blow pipe 12, which in'the operation of the drawing apparatus is raised and lowered with the carriage and bait body. The lower end of the pipe 12 is vertically disposed and extends centrally through the valve 5 and is suitably fixed thereto, the said lower .and vertically disposed end of the pipe extending slidably through a guide opening 13 suitably formed or provided upon' the carriage. The valve 5 is of concavoconvex form and its convex surface is adapted for engagement with the seat wall of the opening 10 vto close communication between the atmosphere and the Iinterior of the bait body, while permitting air to flow into andr through the bait body from the pipe 12. Vlhe sliding engagement between thev carriage and blow pipe 'provides a relatively movable or lost-motion connection between the bait body and the valve or closure membei' 5, and for the purpose of regulating and cont-rolling the degree of lost-motion a horizontal transverse stop bar 14 is provided and suitably secured to the pipe 12, as shown at 15, and this bar is adapted for engagement with stop members 16 on the guide l rails 3 to limit the downward'm'ovement of the valve member, as shown in Fig. 1, so as to arrest the downward motion of the valve member at a point above the bait body and before the latter reaches its limit of downward movement in bringing it-'in contact with the glass 2 in the reservoir 1 in the operation of starting to draw a cylinder.

In .the practical operation of the tool, the

carriage is lowered in the usual manner until the lower portion of the bait body 4 is submerged in the molten glass 2, at which time the valve member 5 will be supported above and in spaced relation to said bait body, as above described and as shown in Fig. 1.

lThe carriage isthen moved upwardly on the drawing operation, the glass adhering to the surface of the bait body to form the neck byy which the glass is drawn and connection made between the bait body and the drawn out cylinder. On the upward movement of the carriage and bait body, the latter will pass above the surface of the molten glass and will be exposed to the cooling effeats of the air, both internally 'and externally until it engages the valve member 5, an internal cooling being effected by the ingress of the air through the opening 10 to the interior of the bait body. 'Hence as will be readily understood, the interior and exterior surfaces of the bait body will be uniformly subjected to the cooling action of the air during the initial portion of the draw and while'the neck is hardening, thus adapting the interior and exterior surfaces of the bait body and neck to contract and stipend to like degrees, the surface tension of the sides of the neck 'also equalized, 'whereby thorough hardening of the neck is permitted and cracking or separation of the same from the bait prevented. The hollow bait' body has a preliminary upward move* ment, during which atmospheric air is admitted thereto, until it comes in contact with the valve or closure member 5, bywwhich the opening 10 vis closed'to shut olf communica tion between the cylinder and the atmosphere and to permitv air to pass into` the cylinder only through the pipe 12 to expand the cylinder in the usual way. During this preliminary movement the neck is hardening and the operator can not by any means prematurely supply air through the blow tube to the cylinder, thus avoiding any sudden or premature cooling of the .interior of lthe bait and neck vof the cylinder and unequal expansion and contraction of the same. Defects in the formation ofthe neck andits adherence to the bait as a result of the supply of compressed air to the cylinder before the neck has hardened will therefore be obviated. During the remainder of ,the draw the hollow bait body is sealed by the valve or, blow head 5l to confine the air from the blow pipe within the cylinder, the air from the blow pipe being admitted at the desired pressure or pressures by means of a controlling valve or other controlling means in the usual. way. After the cylinder has been drawn Iit is detached from the bait and surface of the glass in the receptacle 1 in any ordinary manner and the bait is relowered for the succeeding operation. In the lowering of the bait the carriage will descend with the blow pipe until the movement of the pipe 1s arrested by contact of the bar 14C with the stops 16, thebait body descending until immersed in the molten glass in the receptacle 1 while the valve or closure member 5 is stopped lshort of the full length of travel of the bait to position the parts for a repetition of the operation above described, and as shownV in Fig. 1. By thus controlling the cooling of the surfaces of the bait and portion of the glass forming the neck of the cylinder defects of the character described will be prevented, so that a larger percentage of perfect cylinders may be niade.

l claim l 1. ln a glass drawing apparatus, a vertically movable bait comprising a body having interior and exterior surfaces adapted to be exposed to the cooling effects ofthe atmosphere, and means for controlling communication between the interior surface and the atmosphere to subject such interior surface as well to the normal cooling action of the atn'n'isphere during a preliminary portion of the period of the draw. l Y 2. In a glass drawing apparatus, a verticall v movable bait comprising a hollow body having upper and lower air passages, means arresto lforelosing the upper air passage during a predetermined portion of the period of the draw, said means being operative topermit the bait body to move upward a predetermined distance in the drawing action before closing said air passa e, and means for supplying air to the ho low bait body during the period of closure of said upper air passage.

3.V In a-glass drawing apparatus, a vertically movable bait comprising la hollow body having air passages in the top and bottom thereof, a closure for said upper air passagearranged to permit the baitj body to move upward a predetermined. distance .in the drawing action before closing said air passage, and means for supplying a controlled volume of air to the interior of the hollow bait body during thed period of closure thereof. y

4. In a glass-drawing apparatus, a vertically movable hollow bait body having air passages in the top and bottom thereof, a valve for closing thenpper air passage, means governing said valve to close said passage except during a predetermined ently of the bait body, and means for arrest* ing the downward movement of the valve to a degree less than the downward movement of the bait body.

6.l In a glass drawing-ap aratus, avertically movable hollow bait ody having air bait, body,y a valve for closing the upper air 40 passages in the'topand bottom thereof, -a vertically movable carriage carrying saidI passage,l a blow pipe carrying the valve and slidably connected with the carriage, and means for limiting the downward movement of the valve short of the extent of downward movement of the bait body.

7. In a glass drawing apparatus, a vertically movable hollowl bait .body vhaving air passages in the top Aand bottom thereof, a carriage supporting said bait body, a valve for controlling theupper air passage inthe bait body and having a lost-motion-gonned" tion with the carriage, and means for limiting the vdownward movement o f'the f valve short of the length of downward travel of the bait body.

8. In a glass `drawing" apparatus, a verti" cally movable hollow bait body having air passages in the top and bottom thereof, a

carriage supporting said bait body, a blow head having a lost-motionbgnnection with the carriage and including avalve member controlling the upper air passage in the bait body, and a stop for arresting the, downward movement of the blow head to an eX-44 tent short of the length of downward travel of the bait body. Y

In testimony whereof I affix my signature in presence of two witnesses.

4VILLIM. WESTBURY.

Witnesses:

A. L. NIKON, J. T. PANCoAs'r.

Copies of this patent may be obtained for five cents each, by addressing the ,Commissioner'jof Eatent,

- Washingtomll. 

